1. Field of Invention
The present invention relates to cleaning the interior of tubes.
2. Description of Prior Art
In U.S. Pat. Nos. 3,246,847 and 3,791,583 systems for reciprocating pressurized fluid spraying head cleaning systems are disclosed. These systems utilized pistons to control application of fluid pressure and thereby control advance and retraction of the spraying head. However, in U.S. Pat. No. 3,246,847, the valve which controlled the direction of movement was located at a position in contact with the fluid, which could have particles and debris therein, and the valve could thus become clogged and inoperative. The structure in U.S. Pat. No. 3,791,583 was designed for spray cleaning relatively large vessels such as chemical reactors, storage tanks and the like, and thus was, so far as is known, not readily suitable for cleaning elongate tubular objects, such as pipes and tubes.
In U.S. Pat. No. 3,791,583, previously discussed, and in U.S. Pat. No. 3,601,136, pressurized fluid was used to drive a turbine which moved the remaining parts of the system.
Other types of fluid pressure tube cleaning systems are disclosed in U.S. Pat. Nos. 620,224; 2,494,380; 3,246,660; 3,269,659; 3,377,026; 3,589,388; 3,736,909; 3,794,051; 3,817,262; 3,901,252; 3,903,912; 3,938,535; and 3,987,963.
So far as is known, the typical systems currently used in cleaning heat exchanger tubes have used pneumatic motors to move the cleaning lances into and out of the tubes.